For the construction of modular work place units with technical and electronic cabinets, work consoles and tables, and casings and subassembly units use is made of horizontal and vertical sections with recesses, particularly T-slots, in which nuts are placed for the fixing of components with screws.
German patent publication 2,635,439 C2 discloses a spring nut with a plate and a curved spring web, which is introduced through a slit in a T-slot and can be placed in the latter following a 90.degree. rotation. As a result of the action of the spring web, the spring nut can be displaced in an elongated T-slot and can be held at a given point for fixing modular rails, hinges, etc.
More particularly, in the case of T-slots, in which a side leg is provided with a longitudinally directed perforated grid, it is advantageously possible to use a spring nut having a lockable spring web (DE-G-9,207,805.2). This spring nut permits a stable position fixing to be brought about by a locking element constructed on the spring web and, e.g., in the form of a locking stud. The locking element is locked in the perforated grid in a normal use position of the spring nut, i.e. with a plate of the latter engaging on the insertion slit. On rotating the spring nut by 90.degree. or 180.degree., self-retention of the spring nut occurs by means of a locking stud supported or fixed on the bottom or in the insertion slit.
For many uses, it is unnecessary to provide elongated recesses, particularly the T-slots of a hollow section, with an additional perforated grid. A fixing of additional parts in the vicinity of the insertion slit with a spring nut located in the normal use position is adequate. Preference is given to the use of hollow sections with smooth T-slots extending therethrough.